Curcumin inhibited SARS-CoV-2 infectivity under the co-treatment condition. (A) Representative scheme of co-treatment strategy. (B) The figure represents the reduction of D614G strain titer (PFU/mL) on Vero E6 supernatants after co-treatment treatment with curcumin (from 1.25 to 10 µg/mL). Chloroquine (CQ) was used as a positive control of viral inhibition. Data were presented as median ± IQR (n = 4). Mann–Whitney test ** p ≤ 0.01. Inhibition percentages of 92%, 60.4%, 39.3%, and 2.3% were obtained at 10, 5, 2.5, and 1.25 µg/mL of curcumin, respectively. (C) Representative plaques on Vero E6 cells of the co-treatment strategy of curcumin against SARS-CoV-2 D614G strain.